<?php
/**********************************************************************
	Copyright (C) FrontAccounting, LLC.
	Released under the terms of the GNU General Public License, GPL,
	as published by the Free Software Foundation, either version 3
	of the License, or (at your option) any later version.
	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
	See the License here <http://www.gnu.org/licenses/gpl-3.0.html>.
***********************************************************************/

class SessionManager
{
   	function sessionStart($name, $limit = 0, $path = '/', $domain = null, $secure = null)
	{
		// Set the cookie name
		session_name($name);

		// Set SSL level
		$https = isset($secure) ? $secure : isset($_SERVER['HTTPS']);

		// Set session cookie options
		session_set_cookie_params($limit, $path, $domain, $https, true);
		session_start();

		// Make sure the session hasn't expired, and destroy it if it has
		if ($this->validateSession())
		{
			// Check to see if the session is new or a hijacking attempt
			if(!$this->preventHijacking())
			{
				// Reset session data and regenerate id
				$_SESSION = array();
				$_SESSION['IPaddress'] = $_SERVER['REMOTE_ADDR'];
				$_SESSION['userAgent'] = $_SERVER['HTTP_USER_AGENT'];
				$this->regenerateSession();

			// Give a 5% chance of the session id changing on any request
			}
			elseif (rand(1, 100) <= 5)
			{
				$this->regenerateSession();
			}
		}
		else
		{
			$_SESSION = array();
			session_destroy();
			session_start();
		}
	}

	function preventHijacking()
	{
		if (!isset($_SESSION['IPaddress']) || !isset($_SESSION['userAgent']))
			return false;

		if ($_SESSION['IPaddress'] != $_SERVER['REMOTE_ADDR'])
			return false;

		if ( $_SESSION['userAgent'] != $_SERVER['HTTP_USER_AGENT'])
			return false;

		return true;
	}

	function regenerateSession()
	{
		// If this session is obsolete it means there already is a new id
		if (isset($_SESSION['OBSOLETE']) && ($_SESSION['OBSOLETE'] == true))
			return;

		// Set current session to expire in 10 seconds
		$_SESSION['OBSOLETE'] = true;
		$_SESSION['EXPIRES'] = time() + 60;

		// Create new session without destroying the old one
		session_regenerate_id(false);

		// Grab current session ID and close both sessions to allow other scripts to use them
		$newSession = session_id();
		session_write_close();

		// Set session ID to the new one, and start it back up again
		session_id($newSession);
		session_start();

		// Now we unset the obsolete and expiration values for the session we want to keep
		unset($_SESSION['OBSOLETE']);
		unset($_SESSION['EXPIRES']);
	}

	function validateSession()
	{
		if (isset($_SESSION['OBSOLETE']) && !isset($_SESSION['EXPIRES']) )
			return false;

		if (isset($_SESSION['EXPIRES']) && $_SESSION['EXPIRES'] < time())
			return false;

		return true;
	}
}

function output_html($text)
{
	global $before_box, $Ajax, $messages;
	// Fatal errors are not send to error_handler,
	// so we must check the output
	if ($text && preg_match('/\bFatal error(<.*?>)?:(.*)/i', $text, $m)) {
		$Ajax->aCommands = array();  // Don't update page via ajax on errors
		$text = preg_replace('/\bFatal error(<.*?>)?:(.*)/i','', $text);
		$messages[] = array(E_ERROR, $m[2], null, null);
	}
	$Ajax->run();
	return  in_ajax() ? fmt_errors() : ($before_box.fmt_errors().$text);
}
//----------------------------------------------------------------------------------------

function kill_login()
{
	session_unset();
	session_destroy();
}
//----------------------------------------------------------------------------------------

function login_fail()
{
	global $path_to_root;
	
	header("HTTP/1.1 401 Authorization Required");
	echo "<center><br><br><font size='5' color='red'><b>" . _("Incorrect Password") . "<b></font><br><br>";
	echo "<b>" . _("The user and password combination is not valid for the system.") . "<b><br><br>";

	echo _("If you are not an authorized user, please contact your system administrator to obtain an account to enable you to use the system.");
	echo "<br><a href='$path_to_root/index.php'>" . _("Try again") . "</a>";
	echo "</center>";

	kill_login();
	die();
}

//----------------------------------------------------------------------------------------

function check_page_security($page_security)
{
	global $SysPrefs;
	
	$msg = '';
	
	if (!$_SESSION["wa_current_user"]->check_user_access())
	{
		// notification after upgrade from pre-2.2 version
		$msg = $_SESSION["wa_current_user"]->old_db ?
			 _("Security settings have not been defined for your user account.")
				. "<br>" . _("Please contact your system administrator.")	
			: _("Please remove \$security_groups and \$security_headings arrays from config.php file!");
	} elseif (!$_SESSION['SysPrefs']->db_ok && !$_SESSION["wa_current_user"]->can_access('SA_SOFTWAREUPGRADE')) {
		$msg = _('Access to application has been blocked until database upgrade is completed by system administrator.');
	}
	
	if ($msg){
		display_error($msg);
		end_page();
		kill_login();
		exit;
	}

	if (!$_SESSION["wa_current_user"]->can_access_page($page_security))
	{

		echo "<center><br><br><br><b>";
		echo _("The security settings on your account do not permit you to access this function");
		echo "</b>";
		echo "<br><br><br><br></center>";
		end_page();
		exit;
	}
	if (!$_SESSION['SysPrefs']->db_ok 
		&& !in_array($page_security, array('SA_SOFTWAREUPGRADE', 'SA_OPEN', 'SA_BACKUP')))
	{
		display_error(_('System is blocked after source upgrade until database is updated on System/Software Upgrade page'));
		end_page();
		exit;
	}

}
/*
	Helper function for setting page security level depeding on 
	GET start variable and/or some value stored in session variable.
	Before the call $page_security should be set to default page_security value.
*/
function set_page_security($value=null, $trans = array(), $gtrans = array())
{
	global $page_security;

	// first check is this is not start page call
	foreach($gtrans as $key => $area)
		if (isset($_GET[$key])) {
			$page_security = $area;
			return;
		}

	// then check session value
	if (isset($trans[$value])) {
		$page_security = $trans[$value];
		return;
	}
}

//-----------------------------------------------------------------------------
//	Removing magic quotes from nested arrays/variables
//
function strip_quotes($data)
{
	if(get_magic_quotes_gpc()) {
		if(is_array($data)) {
			foreach($data as $k => $v) {
				$data[$k] = strip_quotes($data[$k]);
			}
		} else
			return stripslashes($data);
	}
	return $data;
}

function html_cleanup(&$parms)
{
	foreach($parms as $name => $value) {
//		$value = @html_entity_decode($value, ENT_QUOTES, $_SESSION['language']->encoding);
		if (is_array($value))
			html_cleanup($parms[$name]);
		else
			$parms[$name] = @htmlspecialchars($value, ENT_QUOTES, $_SESSION['language']->encoding);
	}
	reset($parms); // needed for direct key() usage later throughout the sources
}

//============================================================================
//
//
function login_timeout()
{
	// skip timeout on logout page
	if ($_SESSION["wa_current_user"]->logged) {
		$tout = $_SESSION["wa_current_user"]->timeout;
		if ($tout && (time() > $_SESSION["wa_current_user"]->last_act + $tout))
		{
			$_SESSION["wa_current_user"]->logged = false;
		}
		$_SESSION["wa_current_user"]->last_act = time();
	}
}
//============================================================================
if (!isset($path_to_root))
{
	$path_to_root = ".";
}

// Prevent register_globals vulnerability
if (isset($_GET['path_to_root']) || isset($_POST['path_to_root']))
	die("Restricted access");

include_once($path_to_root . "/includes/errors.inc");
// colect all error msgs
set_error_handler('error_handler' /*, errtypes */);

include_once($path_to_root . "/includes/current_user.inc");
include_once($path_to_root . "/frontaccounting.php");
include_once($path_to_root . "/admin/db/security_db.inc");
include_once($path_to_root . "/includes/lang/language.php");
include_once($path_to_root . "/config_db.php");
include_once($path_to_root . "/includes/ajax.inc");
include_once($path_to_root . "/includes/ui/ui_msgs.inc");
include_once($path_to_root . "/includes/prefs/sysprefs.inc");

include_once($path_to_root . "/includes/hooks.inc");
//
// include all extensions hook files.
//
foreach ($installed_extensions as $ext)
{
	if (file_exists($path_to_root.'/'.$ext['path'].'/hooks.php'))
		include_once($path_to_root.'/'.$ext['path'].'/hooks.php');
}

/*
	Uncomment the setting below when using FA on shared hosting
	to avoid unexpeced session timeouts.
	Make sure this directory exists and is writable!
*/
// ini_set('session.save_path', dirname(__FILE__).'/../tmp/');

ini_set('session.gc_maxlifetime', 36000); // 10hrs

$Session_manager = new SessionManager();
$Session_manager->sessionStart('FA'.md5(dirname(__FILE__)));

// this is to fix the "back-do-you-want-to-refresh" issue - thanx PHPFreaks
header("Cache-control: private");

include_once($path_to_root . "/config.php");
get_text_init();

// Page Initialisation
if (!isset($_SESSION['language']) || !method_exists($_SESSION['language'], 'set_language')) 
{
	$l = array_search_value($dflt_lang, $installed_languages,  'code');
	$_SESSION['language'] = new language($l['name'], $l['code'], $l['encoding'],
	 (isset($l['rtl']) && $l['rtl'] === true) ? 'rtl' : 'ltr');
}

$_SESSION['language']->set_language($_SESSION['language']->code);


include_once($path_to_root . "/includes/access_levels.inc");
include_once($path_to_root . "/version.php");
include_once($path_to_root . "/includes/main.inc");

// Ajax communication object
$Ajax = new Ajax();

// js/php validation rules container
$Validate = array();
// bindings for editors
$Editors = array();
// page help. Currently help for function keys.
$Pagehelp = array();

$Refs = new references();

// intercept all output to destroy it in case of ajax call
register_shutdown_function('end_flush');
ob_start('output_html',0);

if (!isset($_SESSION["wa_current_user"]))
	$_SESSION["wa_current_user"] = new current_user();

html_cleanup($_GET);
html_cleanup($_POST);
html_cleanup($_REQUEST);
html_cleanup($_SERVER);

// logout.php is the only page we should have always 
// accessable regardless of access level and current login status.
if (strstr($_SERVER['PHP_SELF'], 'logout.php') == false){

	login_timeout();

	if (!$_SESSION["wa_current_user"]->old_db)
		include_once($path_to_root . '/company/'.user_company().'/installed_extensions.php');

	install_hooks();

	if (!$_SESSION["wa_current_user"]->logged_in())
	{
		// Show login screen
		if (!isset($_POST["user_name_entry_field"]) or $_POST["user_name_entry_field"] == "")
		{
			// strip ajax marker from uri, to force synchronous page reload
			$_SESSION['timeout'] = array( 'uri'=>preg_replace('/JsHttpRequest=(?:(\d+)-)?([^&]+)/s',
					'', @htmlspecialchars($_SERVER['REQUEST_URI'], ENT_QUOTES, $_SESSION['language']->encoding)), 
				'post' => $_POST);

			include($path_to_root . "/access/login.php");
			if (in_ajax())
				$Ajax->activate('_page_body');
			exit;
		} else {

			$succeed = isset($db_connections[$_POST["company_login_name"]]) &&
				$_SESSION["wa_current_user"]->login($_POST["company_login_name"],
				$_POST["user_name_entry_field"], $_POST["password"]);
			// select full vs fallback ui mode on login
			$_SESSION["wa_current_user"]->ui_mode = $_POST['ui_mode'];
			if (!$succeed)
			{
			// Incorrect password
				login_fail();
			}
			$lang = &$_SESSION['language'];
			$lang->set_language($_SESSION['language']->code);
		}
	} else
		set_global_connection();

	if (!isset($_SESSION["App"])) {
		$_SESSION["App"] = new front_accounting();
		$_SESSION["App"]->init();
	}
}

$SysPrefs = &$_SESSION['SysPrefs'];

// POST vars cleanup needed for direct reuse.
// We quote all values later with db_escape() before db update.
$_POST = strip_quotes($_POST);

?>